Amanita brunnescens - Amanitaceae.org - Taxonomy and Morphology of Amanita and Limacella
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name Amanita brunnescens
name status nomen acceptum
author G. F. Atk.
english name "Brown American Star-Footed Amanita"
synonyms
=Amanita brunnescens var. pallida L. Krieg.
images

  • 1. Amanita brunnescens, Maine, U.S.A.



  • 2. Amanita brunnescens, South Carolina, U.S.A.


  • 3. Amanita brunnescens, New York [state], U.S.A.


  • 4. Amanita brunnescens, South Carolina, U.S.A.

    • intro The following material that is not otherwise attributed in the text is based on original research of R. E. Tulloss.
    cap The cap is pale green-yellow to gray-brown to dark red-brown sometimes with olivaceous tints and often darkest in the center.  It is 70-97 mm wide, and often lined with distinct dark radial fibers.  Infrequently one half of the cap will be pale and the other half will be distinctly brown.  The cap is broadly rounded, bell-shaped, convex or planar.  The cap is dull when moist and shiny when dry.  The flesh of the cap is white except for the pale cream center, and stains brown.  The flesh is 4.5-9 mm above the stem and thins evenly to the smooth edge.  The edge does not have remnants of the volva hanging from it.  The volva is largely absent or if present appears as scattered warts or small patches on the cap, which are easily separated and orange-brown to dark brown in color.
    gills The white to cream white gills are free from the stem to slightly attached, and crowded.  The gills have a faint line and a small downward projection on the top of the stem.  The gills stain brown and are 5.5- - 6+ mm broad.  The short gills are not squarely cut off.
    stem The stem is 90 - 108 × 12 - 15 mm and is cream white above and bellow the ring.  Orange-brown stains develop on the lower half of the stem and on the bulb, which also is finely grooved vertically.  The stem narrows upward, and flares briefly at the top.  The bulb is subglobose to hemispheric and has multiple deep vertical clefts in it.  The flesh of the stem is white, stuffed, and stains orange-brown where insects have tunneled into it.  The cream-white, skirt-like ring is near the top of the stem and is sometimes streaked with brown.  The ring's top surface is radially lined and its bottom surface is smooth.  It can become brown with age.  The white volval remnants become brown with age and sometimes form an incomplete short projection on the top rim of the bulb.
    odor/taste The odor of A. brunnescens suggests freshly dug potatoes, especially in stipe and bulb context when just sectioned.  No taste is recorded.
    spores The spores measure (7.0-) 8.0 - 9.2 (-9.5) × (6.5-) 7.2 - 8.5 (-9.2) µm and are globose to subglobose (occasionally broadly ellipsoid) and amyloid. Clamps are absent from bases of basidia.
    discussion The present species is known from eastern North America.  The reader may wish to compare A. brunnescens to the European species A. asteropus Sabo ex Romagn.

    There is some question as to whether A. aestivalis Singer is a distinct species; however, Singer described it as pure white with or without some yellow over the disk and bruising much more slowly than does A. brunnescens.  At present RET follows Jenkins (1986) in maintaining the two taxa as separate.  Relevant molecular studies have not been completed to date.

    Amanita brunnescens var. pallida L. Krieg. is originally described in such a way as to include both pale citrin collections of A. brunnescens and A. aestivalis. There is no holotype for var. pallida, but there are a number of candidates for a lectotype.

    Note that the cap color in A. brunnescens is very variable; the specimens in photograph 2 (above) were found in close proximity and include cap colors ranging from pale citrin to brown. One cap (second from the viewer's right) is half citrin and half brown.—R. E. Tulloss and N. Goldman
    brief editors RET

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